Re: Tablespace Usage and Performance

On Nov 9, 1:25 pm, Robert Klemme <shortcut..._at_googlemail.com> wrote:
> On 08.11.2008 21:48, DA Morgan wrote:>>>>>> > Robert Klemme wrote:> >> On 08.11.2008 02:49, DA Morgan wrote:> >>> Dereck L. Dietz wrote:> >>>> Oracle 10g 10.2.0.3> >>>> Windows 2003 Server>> >>>> I have someone who made the following statement:>> >>>> "any time a tablespace is > 85% [ of capacity ] we experience> >>>> performance degragation".>> >>>> Is there any validity in that or not?>> >>>> Thanks>> >>> Not!>> >> Hmm, I lean more towards Joel. After all, the statement is just an> >> observation, which we can't really question. The interesting bit is> >> to find out what caused this observation. There may be a common root> >> for both phenomena (for example, heavy insert activity at end of month> >> just before old data is purged, leading to tablespaces filling up AND> >> queries being slow). But of course, there is by far too many detail> >> to only start guessing about something like that. We do not even know> >> what "performance degradation" means. Is it queries, inserts, backup> >> etc.? Just one statement or multiple? ...>> > My point in the simplistic answer is that there may be other things> > going on but there is no 1:1 relationship between available space> > and performance. Could a lack of space mean that there are other> > issues related to performance? Of course. But you can not draw a> > straight line that corresponds with the question asked by the OP.>> I agree with regard to the straight line. I just felt the answer was> probably a bit too simplistic in this case and was trying to avoid> subsequent miscommunications e.g.>> "any time a tablespace is > 85% [ of capacity ] we experience> performance degragation".>> "Can't be.">> "Are you kidding me? Look at these figures: " [EM pops up] "tablespace> is full, query slow.">> ...>> And yes, I confess, I did enjoy the nitpicking. But I felt it could> help speak out the unspoken so I did not resist the "temptation". :-)>> Kind regards>> robert- Hide quoted text ->> - Show quoted text -

>> " [EM pops up] "tablespace is full, query slow." <<

What this example proves is that too many of the programmers Oracle
hires to write its applications do not understand how Oracle works.